1. Field of the Invention
The present invention generally relates to backup memory configuration and transmission systems for communication using the same and, more particularly, to a backup memory configuration in which configuration data for a main CPU package and constituent packages are stored and the consistency of data is maintained, and also to a transmission system for communication using such backup memory configuration.
2. Description of the Related Art
FIG. 19 is a block diagram showing a transmission system for communication according to the related art. Referring to FIG. 19, numeral 190 indicates a package with a main CPU mounted thereon. The package 190 serves as a monitor and control unit and provides a main CPU capability to the system. Numeral 200 indicates a backup memory attached to the main CPU package 190 and storing key codes and configuration data for constituent packages described later. Each of numerals 191-195 indicates a constituent package constituting the transmission system for communication and having respective devices; and 196 indicates an internal bus connecting the main CPU package 190 and each of the constituent packages 191-195. Specifically, the constituent package 195 does not require a parameter package.
In the transmission system for communication according to the related art, parameters and configuration data set in each of the constituent packages 191-194 constituting the system are permanently stored in the backup memory 200 implemented by, for example, a non-volatile memory. In the event that a power failure occurs in the transmission system or a package is exchanged for a substitute package, a key code and configuration data stored in the backup memory 200 are read out upon start-up of the entirety of the system or the substitute package. The key code and configuration data are then sent to the corresponding one of the packages 191-194 so that the package is properly set up, thus causing the system to automatically transit to the normal operating condition. This way, the suspended communication service is promptly resumed.
As the number of parameters set up in the transmission system for communication is increased with an increase in the scale, complexity and versatility of the system, the number of parameters sent from the monitor and control unit to constituent packages when the transmission system is started or when the individual constituent package is started is increased. Accordingly, an intensive load is imposed on the monitor and control unit when the system is started, and a relatively long period of time is required in order to start constituent packages in the system.
Advancement in the functions of the transmission system may require a plurality of constituent packages to operate in cooperation with each other so as to implement a required function. In this case, it is difficult for individual constituent packages to handle the parameters in a manner not affecting the other packages. A requirement thus arises that the data set up for the devices in the packages be consistent. Since the monitor and control unit implemented by the main CPU package 190 should check the consistency upon start-up of the device(s), the load imposed on the main CPU package 190 involving retrieval processes and comparison processes is increased as a result. Consequently, the time required to start the entire system is increased.
Accordingly, a general object of the present invention is to provide a backup memory configuration and a transmission system using the same, in which the aforementioned drawback is eliminated.
Another and more specific object is to provide a backup memory configuration and a transmission system using the same, in which the start-up process of the transmission system for communication is distributed among a plurality of constituent packages constituting the system so that the start-up time is reduced, and in which the consistency of the data set up in the devices in the constituent packages is ensured.
The aforementioned objects can be achieved by a backup memory configuration system for use in a transmission system for communication having a control package provided with a main CPU and a plurality of constituent packages provided with respective devices, and an operation system for supplying configuration data required for operation of the plurality of constituent packages, comprising: backup memories attached to each of the control package and the plurality of constituent packages; wherein each of the control package and the plurality of constituent packages stores, in the backup memory attached to the package, a key code identifying the package and the configuration data for the package; and the control package allocates and distributes the key codes to the plurality of constituent packages that refer to the key code when the transmission system is started, and allocates and distributes the key code to an individual constituent package when the configuration data is set in the individual constituent package.
When a power of any of the plurality of constituent packages is turned on so that the package is started, the key code maintained by the main CPU provided in the control package may be compared with the key code stored in the backup memory for the started package so as to determine whether the package was used in the same transmission system before the power is turned on; when it is determined that the started package was used in the same transmission system before the power is turned on, the key code and the configuration data stored in the backup memory for the started package may be read out so that a start operation is performed using the key code and the configuration data thus read out; and when it is determined that the started package was not used in the same transmission system before the power is turned on, the key code stored in the backup memory for the started package may be discarded so that a start operation is performed using a predetermined default setting.
When it is determined that any of the control package and the plurality of constituent packages is being used in a transmission system different from the transmission system in which the started package was used, the started package notifies one of the control package and the operation system that the package is started with the default setting, and sets the configuration data retrieved from one of the control package and the operation system in the started package.
When it is determined, upon a start-up of the transmission system, that the transmission system is going through an initial start-up process as a result of key code comparison by the main CPU, the main CPU may generate new key codes and transmit the generated key codes to each of the plurality of constituent packages that refer to the key code, whereupon each of the plurality of constituent packages receiving the key code may initiate a start-up operation based on the received key code; and wherein when it is determined that the packages are being started in the same transmission system as a previous transmission system, the key code and the configuration data stored in the backup memories for the packages may be read out so that each of the packages is started based on the key code and the configuration data thus read out.
The key code may be generated using time value output by the time circuit when the system is started.
An indefinite value occurring in a memory area when the transmission system is started may be used as a seed for a random number generator circuit so that the key code is generated based on a value generated by the random number generator circuit.
An indefinite value occurring in a memory area when the transmission system is started may be used as a seed for a counter circuit so that the key code is generated based on a value generated by the counter circuit.
The aforementioned objects can also be achieved by a transmission system for communication comprising: a control package provided with a main CPU; a plurality of constituent packages provided with respective devices; and backup memories attached to each of the control package and the plurality of constituent packages; wherein each of the control package and the plurality of constituent packages stores, in the backup memory for the package, a key code identifying the package and configuration data required for operation of the package; and the control package allocates and distributes the key codes to the plurality of constituent packages when the transmission system is started, and allocates and distributes the key code to an individual constituent package when the configuration data is set in the individual constituent package.
The transmission system may further comprise: a time circuit for outputting a time value; a random number generator circuit for generating a random number using an indefinite value in a memory area as a seed; a counter circuit for generating a value using an indefinite value in the memory area as a seed; a key code generation circuit for generating the key code based on one or a combination of values generated by said time circuit, random number generator circuit and counter circuit.